In a normal uncomplicated pregnancy, the cervix is long and closed until the late third trimester, when it will eventually shorten and dilate around the time when the fetus fully develops and is ready for birth. Contrastingly, in a pregnancy complicated by cervical shortening or advanced cervical dilation, the cervix progresses to shortening or dilation, respectively, well ahead of the normal schedule above. Consequently, certain women with these conditions will result in birth sooner than thirty-seven gestational weeks, when fetal development is incomplete. Hence, this may lead to neonatal mortality and morbidity. To prolong such pregnancy, the clinicians may place a cerclage or a cervical pessary to support the cervix. Based primarily on consensus and expert opinion, it is recommended that cerclage placement may be beneficial if intra-amniotic infection is ruled out. Similar guidelines are suggested for pessary placement. To rule out infection effectively, a highly sensitive detection method is required.
Currently, the detection of bacteria in a sample relies on culture, microscopy and bacterial species-specific polymerase chain reaction (PCR) assays, which only offer low to moderate sensitivity. Such sensitivity could be improved if we can specifically target the bacterial taxa which are differentially abundant in the abnormal (i.e., short/dilated) cervix, but not those which are only part of the “normal” flora residing in a “normal” cervix. However, to-date, there are limited data on those taxa, because the bacterial taxa in the abnormal cervix have not been systematically profiled and compared with those in the “normal” cervix from appropriately-matched women. Given the prevalence and implications of premature birth, there exists a need for new methods to more accurately detect an increased risk of an adverse pregnancy outcome in women, such that preventive measures may be timely taken to reduce or eliminate the chances of premature birth or neonatal complications. This invention fulfills this and other related needs.